xref: /linux/fs/xfs/xfs_bmap_item.c (revision 9052e9c95d908d6c3d7570aadc8898e1d871c8bb)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_format.h"
9 #include "xfs_log_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_bit.h"
12 #include "xfs_shared.h"
13 #include "xfs_mount.h"
14 #include "xfs_defer.h"
15 #include "xfs_inode.h"
16 #include "xfs_trans.h"
17 #include "xfs_trans_priv.h"
18 #include "xfs_bmap_item.h"
19 #include "xfs_log.h"
20 #include "xfs_bmap.h"
21 #include "xfs_icache.h"
22 #include "xfs_bmap_btree.h"
23 #include "xfs_trans_space.h"
24 #include "xfs_error.h"
25 #include "xfs_log_priv.h"
26 #include "xfs_log_recover.h"
27 
28 kmem_zone_t	*xfs_bui_zone;
29 kmem_zone_t	*xfs_bud_zone;
30 
31 static const struct xfs_item_ops xfs_bui_item_ops;
32 
33 static inline struct xfs_bui_log_item *BUI_ITEM(struct xfs_log_item *lip)
34 {
35 	return container_of(lip, struct xfs_bui_log_item, bui_item);
36 }
37 
38 STATIC void
39 xfs_bui_item_free(
40 	struct xfs_bui_log_item	*buip)
41 {
42 	kmem_cache_free(xfs_bui_zone, buip);
43 }
44 
45 /*
46  * Freeing the BUI requires that we remove it from the AIL if it has already
47  * been placed there. However, the BUI may not yet have been placed in the AIL
48  * when called by xfs_bui_release() from BUD processing due to the ordering of
49  * committed vs unpin operations in bulk insert operations. Hence the reference
50  * count to ensure only the last caller frees the BUI.
51  */
52 STATIC void
53 xfs_bui_release(
54 	struct xfs_bui_log_item	*buip)
55 {
56 	ASSERT(atomic_read(&buip->bui_refcount) > 0);
57 	if (atomic_dec_and_test(&buip->bui_refcount)) {
58 		xfs_trans_ail_delete(&buip->bui_item, SHUTDOWN_LOG_IO_ERROR);
59 		xfs_bui_item_free(buip);
60 	}
61 }
62 
63 
64 STATIC void
65 xfs_bui_item_size(
66 	struct xfs_log_item	*lip,
67 	int			*nvecs,
68 	int			*nbytes)
69 {
70 	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
71 
72 	*nvecs += 1;
73 	*nbytes += xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents);
74 }
75 
76 /*
77  * This is called to fill in the vector of log iovecs for the
78  * given bui log item. We use only 1 iovec, and we point that
79  * at the bui_log_format structure embedded in the bui item.
80  * It is at this point that we assert that all of the extent
81  * slots in the bui item have been filled.
82  */
83 STATIC void
84 xfs_bui_item_format(
85 	struct xfs_log_item	*lip,
86 	struct xfs_log_vec	*lv)
87 {
88 	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
89 	struct xfs_log_iovec	*vecp = NULL;
90 
91 	ASSERT(atomic_read(&buip->bui_next_extent) ==
92 			buip->bui_format.bui_nextents);
93 
94 	buip->bui_format.bui_type = XFS_LI_BUI;
95 	buip->bui_format.bui_size = 1;
96 
97 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUI_FORMAT, &buip->bui_format,
98 			xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents));
99 }
100 
101 /*
102  * The unpin operation is the last place an BUI is manipulated in the log. It is
103  * either inserted in the AIL or aborted in the event of a log I/O error. In
104  * either case, the BUI transaction has been successfully committed to make it
105  * this far. Therefore, we expect whoever committed the BUI to either construct
106  * and commit the BUD or drop the BUD's reference in the event of error. Simply
107  * drop the log's BUI reference now that the log is done with it.
108  */
109 STATIC void
110 xfs_bui_item_unpin(
111 	struct xfs_log_item	*lip,
112 	int			remove)
113 {
114 	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
115 
116 	xfs_bui_release(buip);
117 }
118 
119 /*
120  * The BUI has been either committed or aborted if the transaction has been
121  * cancelled. If the transaction was cancelled, an BUD isn't going to be
122  * constructed and thus we free the BUI here directly.
123  */
124 STATIC void
125 xfs_bui_item_release(
126 	struct xfs_log_item	*lip)
127 {
128 	xfs_bui_release(BUI_ITEM(lip));
129 }
130 
131 /*
132  * Allocate and initialize an bui item with the given number of extents.
133  */
134 STATIC struct xfs_bui_log_item *
135 xfs_bui_init(
136 	struct xfs_mount		*mp)
137 
138 {
139 	struct xfs_bui_log_item		*buip;
140 
141 	buip = kmem_cache_zalloc(xfs_bui_zone, GFP_KERNEL | __GFP_NOFAIL);
142 
143 	xfs_log_item_init(mp, &buip->bui_item, XFS_LI_BUI, &xfs_bui_item_ops);
144 	buip->bui_format.bui_nextents = XFS_BUI_MAX_FAST_EXTENTS;
145 	buip->bui_format.bui_id = (uintptr_t)(void *)buip;
146 	atomic_set(&buip->bui_next_extent, 0);
147 	atomic_set(&buip->bui_refcount, 2);
148 
149 	return buip;
150 }
151 
152 static inline struct xfs_bud_log_item *BUD_ITEM(struct xfs_log_item *lip)
153 {
154 	return container_of(lip, struct xfs_bud_log_item, bud_item);
155 }
156 
157 STATIC void
158 xfs_bud_item_size(
159 	struct xfs_log_item	*lip,
160 	int			*nvecs,
161 	int			*nbytes)
162 {
163 	*nvecs += 1;
164 	*nbytes += sizeof(struct xfs_bud_log_format);
165 }
166 
167 /*
168  * This is called to fill in the vector of log iovecs for the
169  * given bud log item. We use only 1 iovec, and we point that
170  * at the bud_log_format structure embedded in the bud item.
171  * It is at this point that we assert that all of the extent
172  * slots in the bud item have been filled.
173  */
174 STATIC void
175 xfs_bud_item_format(
176 	struct xfs_log_item	*lip,
177 	struct xfs_log_vec	*lv)
178 {
179 	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
180 	struct xfs_log_iovec	*vecp = NULL;
181 
182 	budp->bud_format.bud_type = XFS_LI_BUD;
183 	budp->bud_format.bud_size = 1;
184 
185 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUD_FORMAT, &budp->bud_format,
186 			sizeof(struct xfs_bud_log_format));
187 }
188 
189 /*
190  * The BUD is either committed or aborted if the transaction is cancelled. If
191  * the transaction is cancelled, drop our reference to the BUI and free the
192  * BUD.
193  */
194 STATIC void
195 xfs_bud_item_release(
196 	struct xfs_log_item	*lip)
197 {
198 	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
199 
200 	xfs_bui_release(budp->bud_buip);
201 	kmem_cache_free(xfs_bud_zone, budp);
202 }
203 
204 static const struct xfs_item_ops xfs_bud_item_ops = {
205 	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED,
206 	.iop_size	= xfs_bud_item_size,
207 	.iop_format	= xfs_bud_item_format,
208 	.iop_release	= xfs_bud_item_release,
209 };
210 
211 static struct xfs_bud_log_item *
212 xfs_trans_get_bud(
213 	struct xfs_trans		*tp,
214 	struct xfs_bui_log_item		*buip)
215 {
216 	struct xfs_bud_log_item		*budp;
217 
218 	budp = kmem_cache_zalloc(xfs_bud_zone, GFP_KERNEL | __GFP_NOFAIL);
219 	xfs_log_item_init(tp->t_mountp, &budp->bud_item, XFS_LI_BUD,
220 			  &xfs_bud_item_ops);
221 	budp->bud_buip = buip;
222 	budp->bud_format.bud_bui_id = buip->bui_format.bui_id;
223 
224 	xfs_trans_add_item(tp, &budp->bud_item);
225 	return budp;
226 }
227 
228 /*
229  * Finish an bmap update and log it to the BUD. Note that the
230  * transaction is marked dirty regardless of whether the bmap update
231  * succeeds or fails to support the BUI/BUD lifecycle rules.
232  */
233 static int
234 xfs_trans_log_finish_bmap_update(
235 	struct xfs_trans		*tp,
236 	struct xfs_bud_log_item		*budp,
237 	enum xfs_bmap_intent_type	type,
238 	struct xfs_inode		*ip,
239 	int				whichfork,
240 	xfs_fileoff_t			startoff,
241 	xfs_fsblock_t			startblock,
242 	xfs_filblks_t			*blockcount,
243 	xfs_exntst_t			state)
244 {
245 	int				error;
246 
247 	error = xfs_bmap_finish_one(tp, ip, type, whichfork, startoff,
248 			startblock, blockcount, state);
249 
250 	/*
251 	 * Mark the transaction dirty, even on error. This ensures the
252 	 * transaction is aborted, which:
253 	 *
254 	 * 1.) releases the BUI and frees the BUD
255 	 * 2.) shuts down the filesystem
256 	 */
257 	tp->t_flags |= XFS_TRANS_DIRTY;
258 	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);
259 
260 	return error;
261 }
262 
263 /* Sort bmap intents by inode. */
264 static int
265 xfs_bmap_update_diff_items(
266 	void				*priv,
267 	const struct list_head		*a,
268 	const struct list_head		*b)
269 {
270 	struct xfs_bmap_intent		*ba;
271 	struct xfs_bmap_intent		*bb;
272 
273 	ba = container_of(a, struct xfs_bmap_intent, bi_list);
274 	bb = container_of(b, struct xfs_bmap_intent, bi_list);
275 	return ba->bi_owner->i_ino - bb->bi_owner->i_ino;
276 }
277 
278 /* Set the map extent flags for this mapping. */
279 static void
280 xfs_trans_set_bmap_flags(
281 	struct xfs_map_extent		*bmap,
282 	enum xfs_bmap_intent_type	type,
283 	int				whichfork,
284 	xfs_exntst_t			state)
285 {
286 	bmap->me_flags = 0;
287 	switch (type) {
288 	case XFS_BMAP_MAP:
289 	case XFS_BMAP_UNMAP:
290 		bmap->me_flags = type;
291 		break;
292 	default:
293 		ASSERT(0);
294 	}
295 	if (state == XFS_EXT_UNWRITTEN)
296 		bmap->me_flags |= XFS_BMAP_EXTENT_UNWRITTEN;
297 	if (whichfork == XFS_ATTR_FORK)
298 		bmap->me_flags |= XFS_BMAP_EXTENT_ATTR_FORK;
299 }
300 
301 /* Log bmap updates in the intent item. */
302 STATIC void
303 xfs_bmap_update_log_item(
304 	struct xfs_trans		*tp,
305 	struct xfs_bui_log_item		*buip,
306 	struct xfs_bmap_intent		*bmap)
307 {
308 	uint				next_extent;
309 	struct xfs_map_extent		*map;
310 
311 	tp->t_flags |= XFS_TRANS_DIRTY;
312 	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
313 
314 	/*
315 	 * atomic_inc_return gives us the value after the increment;
316 	 * we want to use it as an array index so we need to subtract 1 from
317 	 * it.
318 	 */
319 	next_extent = atomic_inc_return(&buip->bui_next_extent) - 1;
320 	ASSERT(next_extent < buip->bui_format.bui_nextents);
321 	map = &buip->bui_format.bui_extents[next_extent];
322 	map->me_owner = bmap->bi_owner->i_ino;
323 	map->me_startblock = bmap->bi_bmap.br_startblock;
324 	map->me_startoff = bmap->bi_bmap.br_startoff;
325 	map->me_len = bmap->bi_bmap.br_blockcount;
326 	xfs_trans_set_bmap_flags(map, bmap->bi_type, bmap->bi_whichfork,
327 			bmap->bi_bmap.br_state);
328 }
329 
330 static struct xfs_log_item *
331 xfs_bmap_update_create_intent(
332 	struct xfs_trans		*tp,
333 	struct list_head		*items,
334 	unsigned int			count,
335 	bool				sort)
336 {
337 	struct xfs_mount		*mp = tp->t_mountp;
338 	struct xfs_bui_log_item		*buip = xfs_bui_init(mp);
339 	struct xfs_bmap_intent		*bmap;
340 
341 	ASSERT(count == XFS_BUI_MAX_FAST_EXTENTS);
342 
343 	xfs_trans_add_item(tp, &buip->bui_item);
344 	if (sort)
345 		list_sort(mp, items, xfs_bmap_update_diff_items);
346 	list_for_each_entry(bmap, items, bi_list)
347 		xfs_bmap_update_log_item(tp, buip, bmap);
348 	return &buip->bui_item;
349 }
350 
351 /* Get an BUD so we can process all the deferred rmap updates. */
352 static struct xfs_log_item *
353 xfs_bmap_update_create_done(
354 	struct xfs_trans		*tp,
355 	struct xfs_log_item		*intent,
356 	unsigned int			count)
357 {
358 	return &xfs_trans_get_bud(tp, BUI_ITEM(intent))->bud_item;
359 }
360 
361 /* Process a deferred rmap update. */
362 STATIC int
363 xfs_bmap_update_finish_item(
364 	struct xfs_trans		*tp,
365 	struct xfs_log_item		*done,
366 	struct list_head		*item,
367 	struct xfs_btree_cur		**state)
368 {
369 	struct xfs_bmap_intent		*bmap;
370 	xfs_filblks_t			count;
371 	int				error;
372 
373 	bmap = container_of(item, struct xfs_bmap_intent, bi_list);
374 	count = bmap->bi_bmap.br_blockcount;
375 	error = xfs_trans_log_finish_bmap_update(tp, BUD_ITEM(done),
376 			bmap->bi_type,
377 			bmap->bi_owner, bmap->bi_whichfork,
378 			bmap->bi_bmap.br_startoff,
379 			bmap->bi_bmap.br_startblock,
380 			&count,
381 			bmap->bi_bmap.br_state);
382 	if (!error && count > 0) {
383 		ASSERT(bmap->bi_type == XFS_BMAP_UNMAP);
384 		bmap->bi_bmap.br_blockcount = count;
385 		return -EAGAIN;
386 	}
387 	kmem_free(bmap);
388 	return error;
389 }
390 
391 /* Abort all pending BUIs. */
392 STATIC void
393 xfs_bmap_update_abort_intent(
394 	struct xfs_log_item		*intent)
395 {
396 	xfs_bui_release(BUI_ITEM(intent));
397 }
398 
399 /* Cancel a deferred rmap update. */
400 STATIC void
401 xfs_bmap_update_cancel_item(
402 	struct list_head		*item)
403 {
404 	struct xfs_bmap_intent		*bmap;
405 
406 	bmap = container_of(item, struct xfs_bmap_intent, bi_list);
407 	kmem_free(bmap);
408 }
409 
410 const struct xfs_defer_op_type xfs_bmap_update_defer_type = {
411 	.max_items	= XFS_BUI_MAX_FAST_EXTENTS,
412 	.create_intent	= xfs_bmap_update_create_intent,
413 	.abort_intent	= xfs_bmap_update_abort_intent,
414 	.create_done	= xfs_bmap_update_create_done,
415 	.finish_item	= xfs_bmap_update_finish_item,
416 	.cancel_item	= xfs_bmap_update_cancel_item,
417 };
418 
419 /* Is this recovered BUI ok? */
420 static inline bool
421 xfs_bui_validate(
422 	struct xfs_mount		*mp,
423 	struct xfs_bui_log_item		*buip)
424 {
425 	struct xfs_map_extent		*bmap;
426 
427 	/* Only one mapping operation per BUI... */
428 	if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
429 		return false;
430 
431 	bmap = &buip->bui_format.bui_extents[0];
432 
433 	if (bmap->me_flags & ~XFS_BMAP_EXTENT_FLAGS)
434 		return false;
435 
436 	switch (bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
437 	case XFS_BMAP_MAP:
438 	case XFS_BMAP_UNMAP:
439 		break;
440 	default:
441 		return false;
442 	}
443 
444 	if (!xfs_verify_ino(mp, bmap->me_owner))
445 		return false;
446 
447 	if (!xfs_verify_fileext(mp, bmap->me_startoff, bmap->me_len))
448 		return false;
449 
450 	return xfs_verify_fsbext(mp, bmap->me_startblock, bmap->me_len);
451 }
452 
453 /*
454  * Process a bmap update intent item that was recovered from the log.
455  * We need to update some inode's bmbt.
456  */
457 STATIC int
458 xfs_bui_item_recover(
459 	struct xfs_log_item		*lip,
460 	struct list_head		*capture_list)
461 {
462 	struct xfs_bmbt_irec		irec;
463 	struct xfs_bui_log_item		*buip = BUI_ITEM(lip);
464 	struct xfs_trans		*tp;
465 	struct xfs_inode		*ip = NULL;
466 	struct xfs_mount		*mp = lip->li_mountp;
467 	struct xfs_map_extent		*bmap;
468 	struct xfs_bud_log_item		*budp;
469 	xfs_filblks_t			count;
470 	xfs_exntst_t			state;
471 	unsigned int			bui_type;
472 	int				whichfork;
473 	int				iext_delta;
474 	int				error = 0;
475 
476 	if (!xfs_bui_validate(mp, buip)) {
477 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
478 				&buip->bui_format, sizeof(buip->bui_format));
479 		return -EFSCORRUPTED;
480 	}
481 
482 	bmap = &buip->bui_format.bui_extents[0];
483 	state = (bmap->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
484 			XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
485 	whichfork = (bmap->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
486 			XFS_ATTR_FORK : XFS_DATA_FORK;
487 	bui_type = bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
488 
489 	error = xlog_recover_iget(mp, bmap->me_owner, &ip);
490 	if (error)
491 		return error;
492 
493 	/* Allocate transaction and do the work. */
494 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
495 			XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), 0, 0, &tp);
496 	if (error)
497 		goto err_rele;
498 
499 	budp = xfs_trans_get_bud(tp, buip);
500 	xfs_ilock(ip, XFS_ILOCK_EXCL);
501 	xfs_trans_ijoin(tp, ip, 0);
502 
503 	if (bui_type == XFS_BMAP_MAP)
504 		iext_delta = XFS_IEXT_ADD_NOSPLIT_CNT;
505 	else
506 		iext_delta = XFS_IEXT_PUNCH_HOLE_CNT;
507 
508 	error = xfs_iext_count_may_overflow(ip, whichfork, iext_delta);
509 	if (error)
510 		goto err_cancel;
511 
512 	count = bmap->me_len;
513 	error = xfs_trans_log_finish_bmap_update(tp, budp, bui_type, ip,
514 			whichfork, bmap->me_startoff, bmap->me_startblock,
515 			&count, state);
516 	if (error == -EFSCORRUPTED)
517 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bmap,
518 				sizeof(*bmap));
519 	if (error)
520 		goto err_cancel;
521 
522 	if (count > 0) {
523 		ASSERT(bui_type == XFS_BMAP_UNMAP);
524 		irec.br_startblock = bmap->me_startblock;
525 		irec.br_blockcount = count;
526 		irec.br_startoff = bmap->me_startoff;
527 		irec.br_state = state;
528 		xfs_bmap_unmap_extent(tp, ip, &irec);
529 	}
530 
531 	/*
532 	 * Commit transaction, which frees the transaction and saves the inode
533 	 * for later replay activities.
534 	 */
535 	error = xfs_defer_ops_capture_and_commit(tp, ip, capture_list);
536 	if (error)
537 		goto err_unlock;
538 
539 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
540 	xfs_irele(ip);
541 	return 0;
542 
543 err_cancel:
544 	xfs_trans_cancel(tp);
545 err_unlock:
546 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
547 err_rele:
548 	xfs_irele(ip);
549 	return error;
550 }
551 
552 STATIC bool
553 xfs_bui_item_match(
554 	struct xfs_log_item	*lip,
555 	uint64_t		intent_id)
556 {
557 	return BUI_ITEM(lip)->bui_format.bui_id == intent_id;
558 }
559 
560 /* Relog an intent item to push the log tail forward. */
561 static struct xfs_log_item *
562 xfs_bui_item_relog(
563 	struct xfs_log_item		*intent,
564 	struct xfs_trans		*tp)
565 {
566 	struct xfs_bud_log_item		*budp;
567 	struct xfs_bui_log_item		*buip;
568 	struct xfs_map_extent		*extp;
569 	unsigned int			count;
570 
571 	count = BUI_ITEM(intent)->bui_format.bui_nextents;
572 	extp = BUI_ITEM(intent)->bui_format.bui_extents;
573 
574 	tp->t_flags |= XFS_TRANS_DIRTY;
575 	budp = xfs_trans_get_bud(tp, BUI_ITEM(intent));
576 	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);
577 
578 	buip = xfs_bui_init(tp->t_mountp);
579 	memcpy(buip->bui_format.bui_extents, extp, count * sizeof(*extp));
580 	atomic_set(&buip->bui_next_extent, count);
581 	xfs_trans_add_item(tp, &buip->bui_item);
582 	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
583 	return &buip->bui_item;
584 }
585 
586 static const struct xfs_item_ops xfs_bui_item_ops = {
587 	.iop_size	= xfs_bui_item_size,
588 	.iop_format	= xfs_bui_item_format,
589 	.iop_unpin	= xfs_bui_item_unpin,
590 	.iop_release	= xfs_bui_item_release,
591 	.iop_recover	= xfs_bui_item_recover,
592 	.iop_match	= xfs_bui_item_match,
593 	.iop_relog	= xfs_bui_item_relog,
594 };
595 
596 /*
597  * Copy an BUI format buffer from the given buf, and into the destination
598  * BUI format structure.  The BUI/BUD items were designed not to need any
599  * special alignment handling.
600  */
601 static int
602 xfs_bui_copy_format(
603 	struct xfs_log_iovec		*buf,
604 	struct xfs_bui_log_format	*dst_bui_fmt)
605 {
606 	struct xfs_bui_log_format	*src_bui_fmt;
607 	uint				len;
608 
609 	src_bui_fmt = buf->i_addr;
610 	len = xfs_bui_log_format_sizeof(src_bui_fmt->bui_nextents);
611 
612 	if (buf->i_len == len) {
613 		memcpy(dst_bui_fmt, src_bui_fmt, len);
614 		return 0;
615 	}
616 	XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL);
617 	return -EFSCORRUPTED;
618 }
619 
620 /*
621  * This routine is called to create an in-core extent bmap update
622  * item from the bui format structure which was logged on disk.
623  * It allocates an in-core bui, copies the extents from the format
624  * structure into it, and adds the bui to the AIL with the given
625  * LSN.
626  */
627 STATIC int
628 xlog_recover_bui_commit_pass2(
629 	struct xlog			*log,
630 	struct list_head		*buffer_list,
631 	struct xlog_recover_item	*item,
632 	xfs_lsn_t			lsn)
633 {
634 	int				error;
635 	struct xfs_mount		*mp = log->l_mp;
636 	struct xfs_bui_log_item		*buip;
637 	struct xfs_bui_log_format	*bui_formatp;
638 
639 	bui_formatp = item->ri_buf[0].i_addr;
640 
641 	if (bui_formatp->bui_nextents != XFS_BUI_MAX_FAST_EXTENTS) {
642 		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
643 		return -EFSCORRUPTED;
644 	}
645 	buip = xfs_bui_init(mp);
646 	error = xfs_bui_copy_format(&item->ri_buf[0], &buip->bui_format);
647 	if (error) {
648 		xfs_bui_item_free(buip);
649 		return error;
650 	}
651 	atomic_set(&buip->bui_next_extent, bui_formatp->bui_nextents);
652 	/*
653 	 * Insert the intent into the AIL directly and drop one reference so
654 	 * that finishing or canceling the work will drop the other.
655 	 */
656 	xfs_trans_ail_insert(log->l_ailp, &buip->bui_item, lsn);
657 	xfs_bui_release(buip);
658 	return 0;
659 }
660 
661 const struct xlog_recover_item_ops xlog_bui_item_ops = {
662 	.item_type		= XFS_LI_BUI,
663 	.commit_pass2		= xlog_recover_bui_commit_pass2,
664 };
665 
666 /*
667  * This routine is called when an BUD format structure is found in a committed
668  * transaction in the log. Its purpose is to cancel the corresponding BUI if it
669  * was still in the log. To do this it searches the AIL for the BUI with an id
670  * equal to that in the BUD format structure. If we find it we drop the BUD
671  * reference, which removes the BUI from the AIL and frees it.
672  */
673 STATIC int
674 xlog_recover_bud_commit_pass2(
675 	struct xlog			*log,
676 	struct list_head		*buffer_list,
677 	struct xlog_recover_item	*item,
678 	xfs_lsn_t			lsn)
679 {
680 	struct xfs_bud_log_format	*bud_formatp;
681 
682 	bud_formatp = item->ri_buf[0].i_addr;
683 	if (item->ri_buf[0].i_len != sizeof(struct xfs_bud_log_format)) {
684 		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
685 		return -EFSCORRUPTED;
686 	}
687 
688 	xlog_recover_release_intent(log, XFS_LI_BUI, bud_formatp->bud_bui_id);
689 	return 0;
690 }
691 
692 const struct xlog_recover_item_ops xlog_bud_item_ops = {
693 	.item_type		= XFS_LI_BUD,
694 	.commit_pass2		= xlog_recover_bud_commit_pass2,
695 };
696